So forgive me if this is a dumb question, but I'm a bit new to the Wordpress world. I come from an extensive background of using CMSs like Concrete5, Joomla, and a bit of Drupal. But haven't really jumped in to the Wordpress world until now. It seems straight forward, but I feel like I'm missing something...

So I have a site I'm going to be redesigning for a client and I was given a few steadfast requirements:

1. It MUST use Wordpress.
2. It MUST use the "Shopp" eCommerce plugin so that it's compatible with the next item:
3. It MUST use the existing eCC "eCommerce Connector" plugin that they're already using to sync with quickbooks.

These things can't and won't change for any reason, so please don't suggest anything that utilizes other solutions, even if we both know there are better options.